U.S. patent number 4,359,099 [Application Number 06/216,270] was granted by the patent office on 1982-11-16 for portable animal weighing cart.
Invention is credited to William Henslin.
United States Patent |
4,359,099 |
Henslin |
November 16, 1982 |
Portable animal weighing cart
Abstract
A cart for weighing small animals with the cart having a
torsional undercarriage mechanism that directs the weight of an
animal in a weighing pen through a single tension support member
wherein the elastic deformation of the single tension support
member is measured with an electrical resistance strain gauge
mounted on the tension support member and a conventional digital
strain gauge read-out device.
Inventors: |
Henslin; William (Dodge Center,
MN) |
Family
ID: |
22806424 |
Appl.
No.: |
06/216,270 |
Filed: |
December 15, 1980 |
Current U.S.
Class: |
177/140; 177/211;
177/256 |
Current CPC
Class: |
G01G
17/08 (20130101) |
Current International
Class: |
G01G
17/00 (20060101); G01G 17/08 (20060101); G01G
017/08 () |
Field of
Search: |
;177/136,211,256,DIG.9,140,245 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Salter Industrial Measurement Limited, England, Spec. Sheets For
Models 2G100, 235-6, DR-525, New Product..
|
Primary Examiner: Hartary; Joseph W.
Attorney, Agent or Firm: Jacobson and Johnson
Claims
I claim:
1. A combination cart and weighing device having a weighing
pen;
said weighing pen having an opening in the top to place an animal
therein and sufficiently high sides to prevent an animal from
jumping out of said weighing pen;
said weighing pen having a plurality of first members attached to
said weighing pen for transmitting a downward force;
a support frame, said support frame having a first end and a second
end and means thereon to permit movement of said cart and weighing
device from one location to another;
a torsional support system having a plurality of bearing members on
each end of said torsional support system with said plurality of
bearing members pivotally connecting said support frame to said
torsional support system, said torsional support system including a
first half-linkage mounted on said first end of said support frame
and a second half-linkage mounted on said second end of said
support frame with said first half-linkage connected to said second
half-linkage and said first half-linkage and said second
half-linkage extending from said first end of said support frame to
said second end of said support frame;
a tension member located intermediate said first end of said
support frame and said second end of said support frame, said
tension member connected to said weighing pen and to said first
half-linkage and said second half-linkage so that when an animal is
placed in said weighing pen the weight of the animal provides a
downward force on each of said first half-linkage and said second
half-linkage through said bearing members to thereby provide a
tension force on said tension member in proportion to the weight of
the animal in said weighing pen while providing a rigid structure
to support the use of said combination cart and weighing device as
either a cart or a weighing device; and
means mounted on said tension member to measure the strain on said
tension member to thereby provide a signal corresponding to the
weight of an animal in said weighing pen.
2. The invention of claim 1 including a visual read-out device
responsive to the signal produced by the strain on said tension
member.
3. The invention of claim 1 wherein said weighing pen includes a
handle for pushing or pulling said weighing pen and said means on
said support frame comprises wheels to permit said weighing cart to
be moved about.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to weighing carts and, more
specifically, to portable weighing cart for weighing live
animals.
The concept of weighing devices is old in the art with the types of
weighing devices ranging from very simple devices to very
sophisticated devices. Although there are a plethora of weighing
devices available, there is no suitable device to solve the unique
problems that have developed with the application of scientific
principals to raising of small animals. For example, raising of
animals such as pigs requires careful monitoring of the feed and
weight of each individual animal in order for the farmer to select
the pigs which produce the most rapid weight gains. Weighing begins
at birth when the pigs are small and continues as the pigs gain
weight. As a farmer may have many littering pens, it is often
necessary to move the weighing device from one littering pen to
another. In addition, the weighing device must accurately weigh
small animals as well as being subject to the environmental
conditions encountered in a pig raising operation. A further
problem is that small animals usually will not hold still for
weighing. The present invention provides a portable, accurate
weighing cart that can weight live animals even though the animal
may wander in the weighing pen. In addition, the weight scale
functions as a cart that permits easy movement from one area to
another.
2. Description of the Prior Art
The Dale U.S Pat. No. 3,181,635 shows a concept of a portable scale
with a flat platform.
The Gray U.S. Pat. No. 3,191,701 shows a portable weighing
apparatus using fluid load cells for weighing trucks of the
like.
The English, et al. U.S. Pat. No. 3,949,822 shows a vehicle wheel
weighing system device using a strain gauge network for weighing
trucks by measuring the weight on a number of scales.
The Mitchell, et al. U.S. Pat. No. 314,599 shows an early version
of a weighing scale which weighs an object regardless of its
location on the scale.
The Miller U.S. Pat. No. 618,893 shows a combination scoop and
scale with a scoop centrally supported by a spiral spring weighing
device.
More current prior art devices are shown in the attached technical
specification sheets of the Salter Industrial Measurement Limited
of England.
Salter specification sheet (Model 2G100) shows an electronic weight
head for use as an animal weighing scale for large animals wherein
an animal cage and the animal are suspended from an arm hanging
below the scale.
Salter specification sheet (Model 235-6) shows a number of
suspended weighing systems having a single axis weighing unit.
Salter new product information bulletin shows a washable nylon baby
weigh sling for use with a spring suspension scale.
Salter specification sheet (Model DR-525) shows an electronic
flexure base scale which uses a single load cell and stainless
steel flexure located at the corners of the frame. A pivot arm
connected to one side where an off-centered positioned load cell
measures the weight of an object through a digital weight
meter.
A review of these prior art devices reveal that none of the prior
art devices provide the farmer with a portable, accurate weighing
device for weighing small live animals, particularly animals that
may move around.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of my portable weighing cart;
FIG. 2 is a partial view of the torsional undercarriage; and
FIG. 3 is a top sectional view of the connecting mechanism in the
torsional undercarriage.
SUMMARY OF THE INVENTION
Briefly, the invention comprises a portable weighing cart that can
be transported from one area to another with a weighing mechanism
incorporated in the cart. The weighing mechanism comprises a
torsional undercarriage that forms a link between a main support
frame and the weighing pen with the torsional undercarriage
directing the downward forces from weighing an animal through a
single tension member. The undercarriage connects to the frame and
cart through bearing supports with the undercarriage and frame
restrained from displacement motion relative to one another. A
strain gauge and strain gauge read-out device provide a visual
indication of the weight of an animal in the weighing pen.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, reference numeral 10 generally designates my
portable animal weighing cart having a high walled pen 11 for
placing small animals therein. The pen walls are sufficiently high
to prevent an animal from jumping out of pen 11. Pen 11 is mounted
on a main support frame 14 having rollers 15 thereon. A handle 13
located on the top of pen 11 provides means for pushing or pulling
weighing cart 10 from one location to another. Located beneath pen
11 is a torsional undercarriage that transmits the weight of an
object in the pen to a single tension support member fastened to
the bottom of pen 11. Located at the bottom corners of pen 11 are
members 16 which contain bearings therein. Rotatably journaled in
the bearings in members 16 are cross members 18 and extending
outward from cross members 18 are members 22 which are rotatably
mounted in bearings 21 through shaft 20. The bearing members shown
are of the type that mount securely to one surface and contain a
rotatable central member to provide low frictional resistance to
rotation of either shaft 20 or shaft 18; however, as will be
described herein, there is very little rotation of any of the
shafts journaled in the bearings.
FIG. 2 shows a side view of the details of one side of the
torsional undercarriage linkage that supports pen 11 above frame
14. Reference numeral 22 identifies the outward member of length
L.sub.1 which is rigidly connected to member 30 of length L.sub.2
to form a first lever arm. Similarly, there is another vertical
half-linkage located on the other side of cart 10 which has a
member 33 that connects to member 30 to form a second lever arm.
Arrows of force, F.sub.1, F.sub.2 and F.sub.3, are shown to
indicate the forces acting on the right half of the torsional
undercarriage mechanism. Force F.sub.1 is the upward force that
supports pen 11 above frame 14 and is transmitted through outer
bearings 21, i.e., this is the end point of support of the
torsional undercarriage mechanism on frame 14. Similarly, the left
side of the torsional undercarriage mechanism is supported in an
identical manner. F.sub.2 designates the right side downward force
produced by the weight of the pen 11 and the contents of pen 11.
F.sub.3 represents the total tension force on member 34 produced by
the force generated by the right side counterclockwise torque about
right side bearings 18 produced by F.sub.2 about F.sub.1 and the
left side clockwise torque produced by a similar force about the
left side bearing 18.
As can be seen from FIG. 2 and FIG. 3, member 30 and members 22
coact to form a Y-shaped structure on the right side of pen 11 and
similarly member 33 coacts with cross members on the opposite side
to form a Y-shaped structure on the left side of pen 11. The end of
member 30 connects to yoke member 31 through a connecting rod 32.
Similarly, the end of member 33 connects to yoke member 31 also
through connecting rod 32. Yoke member 31 connects to one end of a
tension support member 34 through a similar connecting rod 36. FIG.
3 shows a top view of yoke 31 and the pivotal dovetail relationship
of members 30 and 33. One end of tension support member 34 fastens
securely to the bottom of pen 11 with the other end fastened to
yoke 31. Located on tension support member 34 is a strain gauge 35
which connects to an electronic digital read-out device 12. Strain
gauges are known in the art and comprise an electrical resistance
which is fixed firmly to an object to expand and contract as the
object is stressed. The displacement results in a change in strain
guage electrical resistance which can be converted to a weight
read-out through available electronic instruments.
To more fully understand the operation and use of my invention,
reference should be made to FIG. 1. A farmer grasps handle 13 and
wheels cart 10 proximate the farrowing pen. Next, the operator
turns on the electronic digital read-out 12 which provides a visual
indication of the weight of objects in pen 11. Next, the farmer
places a small animal such as a pig in pen 11. The weight of the
pig increases the right side downward force F.sub.2 through right
side members 16 and right side bearings 18 and a similar downward
force through left side members 16 and left side bearings 18.
However, members 30 and 33 are mechanically restrained from
downward motion through yoke 31 and tension support member 34 which
is rigidly connected to the bottom of pen 11, i.e., support members
16 acting on members 18 prevent downward motion of pen 11. This
restraining produces a single tension F.sub.1 as a result of
torques produced by downward forces on opposite sides of frame 14.
Bearings 18 and 21 have been provided to permit slight downward
rotation of member 33 and member 30, FIG. 2. However, in view of
the position and location of member 16, arms 33 and 30 are
effectively restrained from downward movement by yoke 31 and
tension support member 34 which attaches to the bottom of pen 11.
It is apparent that members 33 and 30 cannot rotate downward and
form part of a rigid structure; however, although pen 11 is not
free to be displaced downward, the torque produced on members 30
and 33 produce a downward force on member 34. As pen 11 is
restrained from downward movement, it is apparent that tension
support member 34 is placed in tension in direct proportion to the
weight of an animal in pen 11. The tension force in member 34
produces an elastic elongation of tension support member 34 which
is measured by a single strain gauge 35 which is centrally located
on the undercarriage of cart 10. A lead 17 connects strain gauge 35
to a visual digital read-out device.
It will thus be appreciated that the weighing unit comprises a
fully restrained undercarriage which is sufficiently rigid so that
cart 10 can be moved from one place to another as if it were a
solid support cart with no weighing mechanism.
It has been found that the present arrangement provides measurement
by the weight of the animal regardless of the location of the
animal in pen 11 through a single tension member 34. Furthermore,
the bearings members provide very low frictional resistance thereby
minimizing hysteresis losses associated with flexible support.
While the weighing unit can weigh small animals to within a tenth
of a pound, the unit is also very rugged since the undercarriage
and pen 11 are joined together in a single unit.
To scale the sensitivity of the weighing cart, the distances
L.sub.1 and L.sub.2 can be varied with an increase in L.sub.2 and
corresponding decrease in L.sub.1 producing a less sensitive unit
and a decrease in L.sub.2 and a corresponding increase in L.sub.1
producing a more sensitive weighing unit.
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